// let arr = ['a', 'b', 'c', 'd', 'e']
// for (let item of arr) {
//   console.log(item);
// }

let obj = {
  name: '啊伟',
  age: 18,
  like: {
    type: 'coding'
  }
}

let data = Object.create(obj)
data.sex = 'boy'

for (let key in data) {
  if (data.hasOwnProperty(key)) {
    console.log(key);
  }
  
}